<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>Bootstrap 101 Template</title>

    <!-- Bootstrap -->
    <link href="css/bootstrap.min.css" rel="stylesheet">

    <!-- HTML5 shim 和 Respond.js 是为了让 IE8 支持 HTML5 元素和媒体查询（media queries）功能 -->
    <!-- 警告：通过 file:// 协议（就是直接将 html 页面拖拽到浏览器中）访问页面时 Respond.js 不起作用 -->
    <!--[if lt IE 9]   以下两个引入可以选择不要删去,重点是另外三个>
    <script src="https://cdn.jsdelivr.net/npm/html5shiv@3.7.3/dist/html5shiv.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/respond.js@1.4.2/dest/respond.min.js"></script>
    <![endif]-->
    <!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
    <script src="https://cdn.jsdelivr.net/npm/jquery@1.12.4/dist/jquery.min.js"></script>
    <!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
    <script src="js/bootstrap.min.js"></script>
</head>
<body>
     <!--class属性当中的"default"值可以更改的;不同的对应值会有不同的效果-->
<a class="btn btn-default" href="#" role="button">Link</a>
<button class="btn btn-default" type="submit">Button</button>
<input class="btn btn-default" type="button" value="Input">
<input class="btn btn-default" type="submit" value="Submit">
     <br>

     <!-- Standard button -->
     <button type="button" class="btn btn-default">（默认样式）Default</button>

     <!-- Provides extra visual weight and identifies the primary action in a set of buttons -->
     <button type="button" class="btn btn-primary">（首选项）Primary</button>

     <!-- Indicates a successful or positive action -->
     <button type="button" class="btn btn-success">（成功）Success</button>

     <!-- Contextual button for informational alert messages -->
     <button type="button" class="btn btn-info">（一般信息）Info</button>

     <!-- Indicates caution should be taken with this action -->
     <button type="button" class="btn btn-warning">（警告）Warning</button>

     <!-- Indicates a dangerous or potentially negative action -->
     <button type="button" class="btn btn-danger">（危险）Danger</button>

     <!-- Deemphasize a button by making it look like a link while maintaining button behavior -->
     <button type="button" class="btn btn-link">（链接）Link</button>
            <hr>

     <!--在加上了"img-responsive"之后,图片的大小在任意设备上都会是100%占比-->
     <img src="Pic/pic.3.jpg" class="img-responsive" >

     <img src="Pic/pic.3.jpg" class="img-rounded"><!--方型-->
     <img src="Pic/pic.3.jpg" class="img-circle"><!--圆型-->
     <img src="Pic/pic.3.jpg" class="img-thumbnail"><!--相框型-->

</body>
</html>